/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Operations/MeshPlaneCut.h
Cut mesh with plane. Assumption is that plane normal is Z value.
FMeshPlaneCut ( [FDynamicMesh3](API\Runtime\GeometryCore\DynamicMesh\FDynamicMesh3) * Mesh, FVector3d Origin, FVector3d Normal )